Does anyone elses JG M16a4 shoot full auto in semi mode?

ok i have a JG M16A4 but wen i pull the semi trigger it shoots like its in full auto,Could it be the lack of lubricants?I bought it from airsplat, and my friends Echo 1 m16a4 works fine but wat is wrong with mine;When i got it it worked fine,Should i yell at asia?